John Chrysostom — as excerpted in the Catena Aurea on Mark 10:1-12

“(ubi sup.) If however he had wished one wife to be put away and another to be brought in, He would have created several women. Nor did God only join one woman to one man, but He also bade a man quit his parents and cleave to his wife. Wherefore it goes on: And he said, (that is, God said by Adam,) For this cause shall a man leave his father and mother, and cleave to his wife. From the very mode of speech, shewing the impossibility of severing marriage, because He said, He shall cleave.”